With the growth of communities and the increase in demand on utilities resulting from such growth together with the demand created by advances in technology, there is an increased requirement to provide additional conductors and the like for purposes of meeting the demand for telecommunication, provision of power and other services in areas which are already built up. As a result, significant infrastructure must be put in place in order to accommodate for the increased demand and in accommodating for the increased demand there can be a significant disruption to existing infrastructure and communities to accommodate existing installations for the additional infrastructure. In built-up areas, this can be particularly difficult as it involves significant disruption. In situations where the appropriate duct-work already exists, the introduction of additional cables also can be particularly disruptive. Even in cases where the existing duct-work enables the introduction of additional cables by “threading’ them through the duct-work the action of “threading” any additional cables into the existing duct-work is time-consuming and labour-intensive. In addition, expanding the additional services to remote locations and to accommodate for the geographic expansion of communities involves considerable cost in laying the cable over fresh ground.
In most communities, a form of railway system exists, whether it be a heavy-duty railway for the transportation of heavy commuter traffic and/or freight or alternatively light rail. Existence of such railways provides the opportunity of associating the required communications ducting with the rail track.
It has been conventional practice to provide ducting for conductors and the like in association with rail track by locating such ducting underground and adjacent to the rail track. This has involved a dual use of the railway land but otherwise presents few savings since the construction and servicing of the rail track forms a totally separate function from the construction and servicing of the ducting. In addition railway authorities have been generally resistant to the dual use of land associated with rail track due to the possibility of damage to the structural integrity of the rail track foundation and disruption to the services provided by the railway. In addition, there have been proposals for providing some duct-work in direct association with a rail track for the purposes of accommodating conductors and telecommunications linkages which are associated with the running of the railway where such duct-work forms a part of the railway structure. Examples of such proposals which have been proposed for railway systems or other track systems are disclosed in AU-A-31645/95, U.S. Pat. No. 5,163,614, U.S. Pat. No. 5,823,114, FR2285491, DE401103, DE19712775, JP4304110 and JP6284542. None of the aforementioned proposals however provide systems whereby additional conductors and the like can be readily introduced into the associated duct-work to improve the carrying capacity.
A difficulty that exists in associating a service such as cabling duct-work with a rail track relates to the need to be able to service such duct-work without causing undue disruption of a railway service associated with the railway track. A further difficulty relates to providing such duct-work with the rail track without the likelihood of adversely affecting the structural integrity of the rail track. It is desirable that if ducting for the purpose of accommodating conductors and the like is associated with rail track such service does not significantly disrupt the operation of the railway associated with the railway track.
The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.